Top Compositeness at the Tevatron and LHC

TL;DR

This paper investigates the hypothesis that the right-handed top quark is composite, analyzing its effects on top pair production at colliders, and suggests that the LHC could detect or constrain top compositeness through enhanced four-top production rates.

Contribution

It provides the first detailed analysis of how top quark compositeness affects collider observables, especially four-top production at the LHC.

Findings

Weak constraint on compositeness scale from Tevatron data

Potential enhancement of four-top production at the LHC by up to 1000 times

LHC can discover or constrain top compositeness across a wide parameter space

Abstract

We explore the possibility that the right-handed top quark is composite. We examine the consequences that compositeness would have on $t \bar{t}$ production at the Tevatron, and derive a weak constraint on the scale of compositeness of order a few hundred GeV from the $t \bar{t}$ inclusive cross section. More detailed studies of differential properties of $t \bar{t}$ production could potentially improve this limit. We find that a composite top can result in an enhancement of the $t \bar{t} t \bar{t}$ production rate at the LHC (of as much as $10^3$ compared to the Standatd Model four top rate). We explore observables which allow us to extract the four top rate from the backgrounds, and show that the LHC can either discover or constrain top compositeness for wide ranges of parameter space.